It was announced via a CGI trailer at Microsoft's E3 2013 press conference, though Microsoft wouldn't say whether it was Halo 5--the second chapter to the Reclaimer trilogy that started with 2012's Halo 4.

Microsoft did say that the new Halo will run on the Xbox One at 60fps, however, which is a first for the series.

The CGI trailer showed a robed figure--later revealed to be Master Chief--walking through a desert, as an alien structure comes out of the ground.